The ultimate goal of this work is to determine the minimum fluoride exposure associated with maximum caries protection in humans. Various regimens which prolong the effective contact time of fluoride are being tested in rats. This includes testing the effects of various fluorides, both organic and inorganic, on dental caries, plaque and its pH. Also synergistic pretreatments and vehicles are being tested. BIBLIOGRAPHIC REFERENCE: Shern, R. J., Duany, L. F., Senning, R. S., and Zinner, D. D.: Clinical Study of an Amine Fluoride Gel and Acidulated Phosphate Fluoride Gel. Community Dent. Oral Epid. 4: 133-136, 1976.